Question 1

A 25.0 mL volume of 0.100 M aspartic acid (monoprotic)  is titrated with 0.100 M NaOH to the equivalence point. If the pH at the equivalence point is 8.28, calculate K a for aspartic acid.

Accepted Answer

A)   1.4×10 - 4
B)   7.3×10 - 4
C)   5.2×10 - 9
D)   1.9×10 - 6
E)   1.0F) A) and D)
G) B) and C)

Question 2

Which pair(s)  of substances would make a suitable buffer pair combination?
I. NaOH and NaBr
II. HF and NaF
III. CH3NH3+Cl -  and CH3NH2

Accepted Answer

A)   I only
B)   II only
C)   III only
D)   I and II
E)   II and IIIF) A) and D)
G) A) and E)

Question 3

Oxalic acid is diprotic with p K al = 1.23 and p K a2 = 4.19. Estimate the pH of a solution of sodium hydrogen oxalate.

Accepted Answer

A)   pH = 3
B)   pH = 5
C)   pH = 7
D)   pH = 9
E)   pH = 11F) A) and D)
G) A) and E)

Question 4

What is the pH of the following solution?
20) 0 mL of 0.50 M acetic acid ( K a = 1.8×10 - 5)  is added tO5 .00 mL of 0.50 M NaOH.

Accepted Answer

A)   4.27
B)   4.74
C)   5.22
D)   5.40
E)   7.00F) None of the above
G) B) and C)

Question 5

The following compounds have very limited solubility in water. Which of the following would dissolve in water under acidic conditions?

Accepted Answer

A)   BaCO3
B)   BaSO4
C)   PbSO4
D)   AgI
E)   CuClF) A) and B)
G) A) and C)

Question 6

Calculate the pH in a solution which is made when 20.0 mL of 0.10 M NH3 ( K b = 1.8×10 - 5)  is added to 30.0 mL of 0.10 M HCl.

Accepted Answer

A)   0.02
B)   1.70
C)   4.57
D)   4.74
E)   9.25F) A) and B)
G) A) and C)

Question 7

What is the pH of an aqueous solution that contains 0.39 M C6H5COOH and 0.14 M C6H5COONa?
K a(C6H5COOH)  = 6.3×10 - 5

Accepted Answer

A)   pH = 0.409
B)   pH = 3.76
C)   pH = 4.65
D)   pH = 6.29
E)   pH = 8.65F) A) and C)
G) B) and E)

Question 8

Which experiment listed below would provide a titration curve that resembles the titration shown below?
3 with standard NaOH (delivered from the burette) . B)  Titrating NH3 with standard HCl (delivered from the burette) . C)  Titrating H3PO4 with standard NaOH (delivered from the burette) . D)  Titrating Na3PO4 with standard HCl (delivered from the burette) . E)  Titrating Na3PO4 with standard NaOH (delivered from the burette) ." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   Titrating NH3 with standard NaOH (delivered from the burette) .
B)   Titrating NH3 with standard HCl (delivered from the burette) .
C)   Titrating H3PO4 with standard NaOH (delivered from the burette) .
D)   Titrating Na3PO4 with standard HCl (delivered from the burette) .
E)   Titrating Na3PO4 with standard NaOH (delivered from the burette) .F) None of the above
G) B) and D)

Question 9

What is the pH after the addition of 0.050 moles of NaOH to 1.00 L of a 0.500 M NH3 / 0.500 M NH4Cl buffer solution?
Assume that there is no volume change on addition of the NaOH. K b for NH3 = 1.8×10 - 5.

Accepted Answer

A)   4.74
B)   4.66
C)   9.34
D)   9.17
E)   9.53F) C) and E)
G) C) and D)

Question 10

A 25.0 mL volume of a 0.200 M N2H4 solution ( K b = 1.70×10 - 6)  is titrated to the equivalence point with 0.100 M HCl. What is the pH of this solution at the equivalence point?
The titration is:
N2H4 + HCl→N2H5+ + Cl -

Accepted Answer

A)   4.70
B)   8.23
C)   7.00
D)   9.30
E)   5.77F) A) and E)
G) B) and E)

Question 11

Which one of these combinations would give a buffer that would be most effective in the pH range 3.0 tO4.0?

Accepted Answer

A)   0.10 M CH3COOH, 0.10 M CH3COONa, K a = 1.8×10 - 5
B)   0.10 M NH4Cl, 0.10 M NH3, K b = 1.8×10 - 5
C)   0.10 M HF, 0.10 M NaF, K a = 3.54×10 - 4
D)   0.10 M H2CO3, 0.10 M NaHCO3, K a = 4.30×10 - 7
E)   0.10 M HCl, 0.10 NaClF) A) and B)
G) B) and E)

Question 12

Consider a buffer solution containing a weak acid, HX, and a salt of the weak acid's conjugate base, NaX. Under what conditions does the pH just equal the p K a of the weak acid?

Accepted Answer

A)   When the p K a equals 7.0.
B)   When [HX] > [NaX].
C)   When [HX] 
D)   When [HX] = [NaX].
E)   When there is no NaX present.F) B) and E)
G) B) and C)

Question 13

Consider the following equilibrium reaction:
NH₃+ H₂ O  NH ₄+ + OH - K b (NH ₃)  = 1.8 10 - 5 Qualitatively, what is the effect of adding NaOH to an aqueous solution of NH₃as shown in the equilibrium reaction above?
(Use Le Chatelier s principle.)

Accepted Answer

A)   The equilibrium will shift left favoring the reactant side and the pH will drop.
B)   The equilibrium will shift right favoring the product side and the pH will drop.
C)   There will be no shift in the equilibrium reaction and the pH will remain constant.
D)   The equilibrium will shift left favoring the reactant side and the pH will rise.
E)   The equilibrium will shift right favoring the product side and the pH will rise.F) None of the above
G) A) and E)

Question 14

What is the pH of an aqueous solution that contains 0.183 M sodium formate (NaCHO2)  and 0.300 M in formic acid?
K a(HCHO2)  = 1.8×10 - 4

Accepted Answer

A)   pH = 3.53
B)   pH = 3.96
C)   pH = 4.56
D)   pH = 5.16
E)   pH = 8.13F) C) and E)
G) D) and E)

Question 15

What is the pH of an aqueous solution that contains 0.085 M HNO2 and 0.10 M potassium nitrite (KNO2) ?
K a(HNO2)  = 4.5×10 - 4

Accepted Answer

A)   pH = 3.27
B)   pH = 3.42
C)   pH = 4.28
D)   pH = 4.42
E)   pH = 7.87F) A) and B)
G) C) and E)

Question 16

Exhibit 16-2 Consider titrating CH3COOH with standard NaOH (delivered from the burette)  to answer the following question(s) .
-Refer to Exhibit 16-2. How would the pH be determined for the aqueous solution in the titration above at the equivalence point ?

Accepted Answer

A)   The pH would equal 7.0 at the equivalence point.
B)   The pH is determined by the Henderson-Hasselbalch equation.
C)   The pH is determined by taking - log[CH3COOH]original.
D)   The pH is determined by solving for the pH of a basic salt.
E)   The pH is determined by solving for the pH of an acidic salt.F) A) and D)
G) A) and C)

Question 17

Calculate the pH of a solution that is 0.78 M NH3 and 0.140 M NH4NO3. K b = 1.8×10 - 5 for NH3.

Accepted Answer

A)   4.00
B)   10.00
C)   4.74
D)   9.26
E)   13.91F) A) and B)
G) C) and D)

Question 18

Which of the following titration curves listed below best represents a curve for the complete titration of citric acid, H3C6H5O7, a triprotic acid with a strong base such as NaOH?

Accepted Answer

A)   3C6H5O7, a triprotic acid with a strong base such as NaOH? 
A)     
B)     
C)     
D)     
E)    " class="answers-bank-image d-inline" rel="preload" >
B)   3C6H5O7, a triprotic acid with a strong base such as NaOH? 
A)     
B)     
C)     
D)     
E)    " class="answers-bank-image d-inline" rel="preload" >
C)   3C6H5O7, a triprotic acid with a strong base such as NaOH? 
A)     
B)     
C)     
D)     
E)    " class="answers-bank-image d-inline" rel="preload" >
D)   3C6H5O7, a triprotic acid with a strong base such as NaOH? 
A)     
B)     
C)     
D)     
E)    " class="answers-bank-image d-inline" rel="preload" >
E)   3C6H5O7, a triprotic acid with a strong base such as NaOH? 
A)     
B)     
C)     
D)     
E)    " class="answers-bank-image d-inline" rel="preload" >F) A) and E)
G) A) and D)

Question 19

If it takes 32.0 mL of 0.100 M HCl to titrate 25.0 mL of a Ba(OH) 2 solution to the equivalence point, what is the molarity of the original Ba(OH) 2 solution?

Accepted Answer

A)   0.128 M
B)   3.20×10 - 2 M
C)   0.256 M
D)   6.40×10 - 2 M
E)   0.100 MF) A) and E)
G) C) and D)

Question 20

A solution of HCOOH ( K a = 1.8×10 - 4)  and HCOO -  was submitted for chemical analysis. The results were:
[HCOOH] = 0.050 M, [HCOO - ] = 0.15 M. Calculate the pH.

Accepted Answer

A)   4.22
B)   3.74
C)   3.27
D)   1.30
E)   - 1.30F) All of the above
G) None of the above

Exam 16: Reactions Between Acids and Bases

Exhibit 16-2 Consider titrating CH3COOH with standard NaOH (delivered from the burette) to answer the following question(s) . -Refer to Exhibit 16-2. How would the pH be determined for the aqueous solution in the titration above at the equivalence point ?

Correct AnswerverifiedShow Answer

What is the pH after the addition of 0.050 moles of NaOH to 1.00 L of a 0.500 M NH3 / 0.500 M NH4Cl buffer solution? Assume that there is no volume change on addition of the NaOH. K b for NH3 = 1.8×10 - 5.

Correct AnswerverifiedShow Answer

Consider the following equilibrium reaction: NH₃+ H₂ O NH ₄+ + OH - K b (NH ₃) = 1.8 10 - 5 Qualitatively, what is the effect of adding NaOH to an aqueous solution of NH₃as shown in the equilibrium reaction above? (Use Le Chatelier s principle.)

Correct AnswerverifiedShow Answer

Which one of these combinations would give a buffer that would be most effective in the pH range 3.0 tO4.0?

Correct AnswerverifiedShow Answer

The following compounds have very limited solubility in water. Which of the following would dissolve in water under acidic conditions?

Correct AnswerverifiedShow Answer

Oxalic acid is diprotic with p K al = 1.23 and p K a2 = 4.19. Estimate the pH of a solution of sodium hydrogen oxalate.

Correct AnswerverifiedShow Answer

A 25.0 mL volume of 0.100 M aspartic acid (monoprotic) is titrated with 0.100 M NaOH to the equivalence point. If the pH at the equivalence point is 8.28, calculate K a for aspartic acid.

Correct AnswerverifiedShow Answer

A solution of HCOOH ( K a = 1.8×10 - 4) and HCOO - was submitted for chemical analysis. The results were: [HCOOH] = 0.050 M, [HCOO - ] = 0.15 M. Calculate the pH.

Correct AnswerverifiedShow Answer

What is the pH of an aqueous solution that contains 0.183 M sodium formate (NaCHO2) and 0.300 M in formic acid? K a(HCHO2) = 1.8×10 - 4

Correct AnswerverifiedShow Answer

Calculate the pH in a solution which is made when 20.0 mL of 0.10 M NH3 ( K b = 1.8×10 - 5) is added to 30.0 mL of 0.10 M HCl.

Correct AnswerverifiedShow Answer

If it takes 32.0 mL of 0.100 M HCl to titrate 25.0 mL of a Ba(OH) 2 solution to the equivalence point, what is the molarity of the original Ba(OH) 2 solution?

Correct AnswerverifiedShow Answer

What is the pH of an aqueous solution that contains 0.085 M HNO2 and 0.10 M potassium nitrite (KNO2) ? K a(HNO2) = 4.5×10 - 4

Correct AnswerverifiedShow Answer

Which of the following titration curves listed below best represents a curve for the complete titration of citric acid, H3C6H5O7, a triprotic acid with a strong base such as NaOH?

Correct AnswerverifiedShow Answer

What is the pH of the following solution? 20) 0 mL of 0.50 M acetic acid ( K a = 1.8×10 - 5) is added tO5 .00 mL of 0.50 M NaOH.

Correct AnswerverifiedShow Answer

What is the pH of an aqueous solution that contains 0.39 M C6H5COOH and 0.14 M C6H5COONa? K a(C6H5COOH) = 6.3×10 - 5

Correct AnswerverifiedShow Answer

Consider a buffer solution containing a weak acid, HX, and a salt of the weak acid's conjugate base, NaX. Under what conditions does the pH just equal the p K a of the weak acid?

Correct AnswerverifiedShow Answer

Which experiment listed below would provide a titration curve that resembles the titration shown below?

Correct AnswerverifiedShow Answer

Calculate the pH of a solution that is 0.78 M NH3 and 0.140 M NH4NO3. K b = 1.8×10 - 5 for NH3.

Correct AnswerverifiedShow Answer

Which pair(s) of substances would make a suitable buffer pair combination? I. NaOH and NaBr II. HF and NaF III. CH3NH3+Cl - and CH3NH2

Correct AnswerverifiedShow Answer

A 25.0 mL volume of a 0.200 M N2H4 solution ( K b = 1.70×10 - 6) is titrated to the equivalence point with 0.100 M HCl. What is the pH of this solution at the equivalence point? The titration is: N2H4 + HCl→N2H5+ + Cl -

Correct AnswerverifiedShow Answer

Exhibit 16-2 Consider titrating CH₃COOH with standard NaOH (delivered from the burette) to answer the following question(s) . -Refer to Exhibit 16-2. How would the pH be determined for the aqueous solution in the titration above at the equivalence point ?

Correct Answer
verified

What is the pH after the addition of 0.050 moles of NaOH to 1.00 L of a 0.500 M NH₃ / 0.500 M NH₄Cl buffer solution? Assume that there is no volume change on addition of the NaOH. K _b for NH₃ = 1.8×10^{- 5}.

Correct Answer
verified

Correct Answer
verified

Which one of these combinations would give a buffer that would be most effective in the pH range 3.0 tO₄.0?

Correct Answer
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Correct Answer
verified

Oxalic acid is diprotic with p K _al = 1.23 and p K _a2 = 4.19. Estimate the pH of a solution of sodium hydrogen oxalate.

Correct Answer
verified

A 25.0 mL volume of 0.100 M aspartic acid (monoprotic) is titrated with 0.100 M NaOH to the equivalence point. If the pH at the equivalence point is 8.28, calculate K _a for aspartic acid.

Correct Answer
verified

A solution of HCOOH ( K _a = 1.8×10^{- 4}) and HCOO^- was submitted for chemical analysis. The results were: [HCOOH] = 0.050 M, [HCOO^-] = 0.15 M. Calculate the pH.

Correct Answer
verified

What is the pH of an aqueous solution that contains 0.183 M sodium formate (NaCHO₂) and 0.300 M in formic acid? K _a(HCHO₂) = 1.8×10^{- 4}

Correct Answer
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Calculate the pH in a solution which is made when 20.0 mL of 0.10 M NH₃ ( K _b = 1.8×10^{- 5}) is added to 30.0 mL of 0.10 M HCl.

Correct Answer
verified

If it takes 32.0 mL of 0.100 M HCl to titrate 25.0 mL of a Ba(OH) ₂ solution to the equivalence point, what is the molarity of the original Ba(OH) ₂ solution?

Correct Answer
verified

What is the pH of an aqueous solution that contains 0.085 M HNO₂ and 0.10 M potassium nitrite (KNO₂) ? K _a(HNO₂) = 4.5×10^{- 4}

Correct Answer
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Which of the following titration curves listed below best represents a curve for the complete titration of citric acid, H₃C₆H₅O₇, a triprotic acid with a strong base such as NaOH?

Correct Answer
verified

What is the pH of the following solution? 20) 0 mL of 0.50 M acetic acid ( K _a = 1.8×10^{- 5}) is added tO₅ .00 mL of 0.50 M NaOH.

Correct Answer
verified

What is the pH of an aqueous solution that contains 0.39 M C₆H₅COOH and 0.14 M C₆H₅COONa? K _a(C₆H₅COOH) = 6.3×10^{- 5}

Correct Answer
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Consider a buffer solution containing a weak acid, HX, and a salt of the weak acid's conjugate base, NaX. Under what conditions does the pH just equal the p K _a of the weak acid?

Correct Answer
verified

Correct Answer
verified

Calculate the pH of a solution that is 0.78 M NH₃ and 0.140 M NH₄NO₃. K _b = 1.8×10^{- 5} for NH₃.

Correct Answer
verified

Which pair(s) of substances would make a suitable buffer pair combination? I. NaOH and NaBr II. HF and NaF III. CH₃NH₃⁺Cl^- and CH₃NH₂

Correct Answer
verified

A 25.0 mL volume of a 0.200 M N₂H₄ solution ( K _b = 1.70×10^{- 6}) is titrated to the equivalence point with 0.100 M HCl. What is the pH of this solution at the equivalence point? The titration is: N₂H₄ + HCl→N₂H₅⁺ + Cl^-

Correct Answer
verified